As small-sized, large capacitance, and low ESR (Equivalent Series Resistance) capacitors, promising candidates are electrolytic capacitors including an anode body on which a dielectric layer is formed and a conductive polymer layer formed so as to cover at least a part of the dielectric layer.
In Unexamined Japanese Patent Publication No. 2008-010657, proposes an electrolytic capacitor obtained by impregnating with an electrolyte solution a capacitor element is proposed. The electrolytic capacitor includes an anode foil on which a dielectric layer is formed, a cathode foil, a separator interposed between the anode foil and the cathode foil, and a conductive polymer layer formed on surfaces of the dielectric layer, the separator, and the cathode foil.
In Unexamined Japanese Patent Publication No. 2006-100478, it is proposed that, from the viewpoint of increasing adhesion between aluminum and a carbon-containing layer in a cathode of a solid electrolytic capacitor, an interposing layer including aluminum carbide is formed between the aluminum and the carbon-containing layer, the carbon-containing layer being formed on a surface of the aluminum.